SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e73cf9e356f855a4b9a9493f29d5b5a81675640472fe818ffcfea2a891ba05c3' 
  AND token = 'eD4vKXTcoTwGKM2eXrj+vs1U9c1zE7FI2HQQUiusBG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}